I have tested with a laptop with an intel wireless card. (I call this laptop PC C) This works perfectly. PC A is connected via wired network, and serving the game. PC C is connected via wireless. Now I can play the game without any problem.
PC C is running knoppix 6.2, wine-1.0.1-174-gc4039bd ,kernel 2.6.31.6
The wireless card: Network controller: Intel Corporation Wireless WiFi Link 5100
I think this is not a problem of wine, but rather a problem of the broadcom wireless card, or the broadcom driver.
Best regards,
Cedric